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Diffstat (limited to 'libjava/classpath/javax/swing/DefaultBoundedRangeModel.java')
| -rw-r--r-- | libjava/classpath/javax/swing/DefaultBoundedRangeModel.java | 475 |
1 files changed, 475 insertions, 0 deletions
diff --git a/libjava/classpath/javax/swing/DefaultBoundedRangeModel.java b/libjava/classpath/javax/swing/DefaultBoundedRangeModel.java new file mode 100644 index 000000000..c1d0fe74a --- /dev/null +++ b/libjava/classpath/javax/swing/DefaultBoundedRangeModel.java @@ -0,0 +1,475 @@ +/* DefaultBoundedRangeModel.java -- Default implementation + of BoundedRangeModel. + Copyright (C) 2002, 2004, 2005, 2006, Free Software Foundation, Inc. + +This file is part of GNU Classpath. + +GNU Classpath is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2, or (at your option) +any later version. + +GNU Classpath is distributed in the hope that it will be useful, but +WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +General Public License for more details. + +You should have received a copy of the GNU General Public License +along with GNU Classpath; see the file COPYING. If not, write to the +Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA +02110-1301 USA. + +Linking this library statically or dynamically with other modules is +making a combined work based on this library. Thus, the terms and +conditions of the GNU General Public License cover the whole +combination. + +As a special exception, the copyright holders of this library give you +permission to link this library with independent modules to produce an +executable, regardless of the license terms of these independent +modules, and to copy and distribute the resulting executable under +terms of your choice, provided that you also meet, for each linked +independent module, the terms and conditions of the license of that +module. An independent module is a module which is not derived from +or based on this library. If you modify this library, you may extend +this exception to your version of the library, but you are not +obligated to do so. If you do not wish to do so, delete this +exception statement from your version. */ + + +package javax.swing; + +import java.io.IOException; +import java.io.ObjectInputStream; +import java.io.ObjectOutputStream; +import java.io.Serializable; +import java.util.EventListener; + +import javax.swing.event.ChangeEvent; +import javax.swing.event.ChangeListener; +import javax.swing.event.EventListenerList; + +/** + * The default implementation of <code>BoundedRangeModel</code>. + * + * @author Andrew Selkirk (aselkirk@sympatico.ca) + * @author Sascha Brawer (brawer@dandelis.ch) + */ +public class DefaultBoundedRangeModel + implements BoundedRangeModel, Serializable +{ + /** + * The identifier of this class in object serialization. Verified + * using the serialver tool of Sun J2SE 1.4.1_01. + */ + private static final long serialVersionUID = 5034068491295259790L; + + /** + * An event that is sent to all registered {@link ChangeListener}s + * when the state of this range model has changed. + * + * <p>The event object is created on demand, the first time it + * is actually needed.</p> + * + * @see #fireStateChanged() + */ + protected transient ChangeEvent changeEvent; + + /** + * The list of the currently registered EventListeners. + */ + protected EventListenerList listenerList = new EventListenerList(); + + /** + * The current value of the range model, which is always between + * {@link #minimum} and ({@link #maximum} - {@link #extent}). In a + * scroll bar visualization of a {@link BoundedRangeModel}, the + * <code>value</code> is displayed as the position of the thumb. + */ + private int value; + + /** + * The current extent of the range model, which is a number greater + * than or equal to zero. In a scroll bar visualization of a {@link + * BoundedRangeModel}, the <code>extent</code> is displayed as the + * size of the thumb. + */ + private int extent; + + /** + * The current minimum value of the range model, which is always + * less than or equal to {@link #maximum}. + */ + private int minimum; + + /** + * The current maximum value of the range model, which is always + * greater than or equal to {@link #minimum}. + */ + private int maximum; + + /** + * A property that indicates whether the value of this {@link + * BoundedRangeModel} is going to change in the immediate future. + */ + private boolean isAdjusting; + + /** + * Constructs a <code>DefaultBoundedRangeModel</code> with default + * values for the properties. The properties <code>value</code>, + * <code>extent</code> and <code>minimum</code> will be initialized + * to zero; <code>maximum</code> will be set to 100; the property + * <code>valueIsAdjusting</code> will be <code>false</code>. + */ + public DefaultBoundedRangeModel() + { + // The fields value, extent, minimum have the default value 0, and + // isAdjusting is already false. These fields no not need to be + // set explicitly. + maximum = 100; + } + + /** + * Constructs a <code>DefaultBoundedRangeModel</code> with the + * specified values for some properties. + * + * @param value the initial value of the range model, which must be + * a number between <code>minimum</code> and <code>(maximum - + * extent)</code>. In a scroll bar visualization of a {@link + * BoundedRangeModel}, the <code>value</code> is displayed as the + * position of the thumb. + * @param extent the initial extent of the range model, which is a + * number greater than or equal to zero. In a scroll bar + * visualization of a {@link BoundedRangeModel}, the + * <code>extent</code> is displayed as the size of the thumb. + * @param minimum the initial minimal value of the range model. + * @param maximum the initial maximal value of the range model. + * + * @throws IllegalArgumentException if the following condition is + * not satisfied: <code>minimum <= value <= value + extent <= + * maximum</code>. + */ + public DefaultBoundedRangeModel(int value, int extent, int minimum, + int maximum) + { + if (!(minimum <= value && extent >= 0 && (value + extent) <= maximum)) + throw new IllegalArgumentException(); + + this.value = value; + this.extent = extent; + this.minimum = minimum; + this.maximum = maximum; + + // The isAdjusting field already has a false value by default. + } + + /** + * Returns a string with all relevant properties of this range + * model. + * + * @return a string representing the object + */ + public String toString() + { + return getClass().getName() + + "[value=" + value + + ", extent=" + extent + + ", min=" + minimum + + ", max=" + maximum + + ", adj=" + isAdjusting + + ']'; + } + + /** + * Returns the current value of this bounded range model. In a + * scroll bar visualization of a {@link BoundedRangeModel}, the + * <code>value</code> is displayed as the position of the thumb. + * + * @return the value + */ + public int getValue() + { + return value; + } + + /** + * Changes the current value of this bounded range model. In a + * scroll bar visualization of a {@link BoundedRangeModel}, the + * <code>value</code> is displayed as the position of the thumb; + * changing the <code>value</code> of a scroll bar's model + * thus moves the thumb to a different position. + * + * @param value the value + */ + public void setValue(int value) + { + value = Math.max(minimum, value); + if (value + extent > maximum) + value = maximum - extent; + + if (value != this.value) + { + this.value = value; + fireStateChanged(); + } + } + + /** + * Returns the current extent of this bounded range model, which is + * a number greater than or equal to zero. In a scroll bar + * visualization of a {@link BoundedRangeModel}, the + * <code>extent</code> is displayed as the size of the thumb. + * + * @return the extent + */ + public int getExtent() + { + return extent; + } + + /** + * Changes the current extent of this bounded range model. In a + * scroll bar visualization of a {@link BoundedRangeModel}, the + * <code>extent</code> is displayed as the size of the thumb. + * + * @param extent the new extent of the range model, which is a + * number greater than or equal to zero. + */ + public void setExtent(int extent) + { + extent = Math.max(extent, 0); + if (value + extent > maximum) + extent = maximum - value; + + if (extent != this.extent) + { + this.extent = extent; + fireStateChanged(); + } + } + + /** + * Returns the current minimal value of this bounded range model. + */ + public int getMinimum() + { + return minimum; + } + + /** + * Changes the current minimal value of this bounded range model. + * + * @param minimum the new minimal value. + */ + public void setMinimum(int minimum) + { + int value, maximum; + + maximum = Math.max(minimum, this.maximum); + value = Math.max(minimum, this.value); + + setRangeProperties(value, extent, minimum, maximum, isAdjusting); + } + + /** + * Returns the current maximal value of this bounded range model. + * + * @return the maximum + */ + public int getMaximum() + { + return maximum; + } + + /** + * Changes the current maximal value of this bounded range model. + * + * @param maximum the new maximal value. + */ + public void setMaximum(int maximum) + { + int value, extent, minimum; + + minimum = Math.min(this.minimum, maximum); + extent = Math.min(this.extent, maximum - minimum); + value = Math.min(this.value, maximum - extent); + + setRangeProperties(value, extent, minimum, maximum, isAdjusting); + } + + /** + * Returns whether or not the value of this bounded range model is + * going to change in the immediate future. Scroll bars set this + * property to <code>true</code> while the thumb is being dragged + * around; when the mouse is relased, they set the property to + * <code>false</code> and post a final {@link ChangeEvent}. + * + * @return <code>true</code> if the value will change soon again; + * <code>false</code> if the value will probably not change soon. + */ + public boolean getValueIsAdjusting() + { + return isAdjusting; + } + + /** + * Specifies whether or not the value of this bounded range model is + * going to change in the immediate future. Scroll bars set this + * property to <code>true</code> while the thumb is being dragged + * around; when the mouse is relased, they set the property to + * <code>false</code>. + * + * @param isAdjusting <code>true</code> if the value will change + * soon again; <code>false</code> if the value will probably not + * change soon. + */ + public void setValueIsAdjusting(boolean isAdjusting) + { + if (isAdjusting == this.isAdjusting) + return; + + this.isAdjusting = isAdjusting; + fireStateChanged(); + } + + /** + * Sets all properties. + * + * @param value the new value of the range model. In a scroll bar + * visualization of a {@link BoundedRangeModel}, the + * <code>value</code> is displayed as the position of the thumb. + * @param extent the new extent of the range model, which is a + * number greater than or equal to zero. In a scroll bar + * visualization of a {@link BoundedRangeModel}, the + * <code>extent</code> is displayed as the size of the thumb. + * @param minimum the new minimal value of the range model. + * @param maximum the new maximal value of the range model. + * @param isAdjusting whether or not the value of this bounded range + * model is going to change in the immediate future. Scroll bars set + * this property to <code>true</code> while the thumb is being + * dragged around; when the mouse is relased, they set the property + * to <code>false</code>. + */ + public void setRangeProperties(int value, int extent, int minimum, + int maximum, boolean isAdjusting) + { + minimum = Math.min(Math.min(minimum, maximum), value); + maximum = Math.max(value, maximum); + if (extent + value > maximum) + extent = maximum - value; + extent = Math.max(0, extent); + + if ((value == this.value) + && (extent == this.extent) + && (minimum == this.minimum) + && (maximum == this.maximum) + && (isAdjusting == this.isAdjusting)) + return; + + this.value = value; + this.extent = extent; + this.minimum = minimum; + this.maximum = maximum; + this.isAdjusting = isAdjusting; + + fireStateChanged(); + } + + /** + * Subscribes a ChangeListener to state changes. + * + * @param listener the listener to be subscribed. + */ + public void addChangeListener(ChangeListener listener) + { + listenerList.add(ChangeListener.class, listener); + } + + /** + * Cancels the subscription of a ChangeListener. + * + * @param listener the listener to be unsubscribed. + */ + public void removeChangeListener(ChangeListener listener) + { + listenerList.remove(ChangeListener.class, listener); + } + + /** + * Sends a {@link ChangeEvent} to any registered {@link + * ChangeListener}s. + * + * @see #addChangeListener(ChangeListener) + * @see #removeChangeListener(ChangeListener) + */ + protected void fireStateChanged() + { + ChangeListener[] listeners = getChangeListeners(); + + if (changeEvent == null) + changeEvent = new ChangeEvent(this); + + for (int i = listeners.length - 1; i >= 0; --i) + listeners[i].stateChanged(changeEvent); + } + + /** + * Retrieves the current listeners of the specified class. + * + * @param listenerType the class of listeners; usually {@link + * ChangeListener}<code>.class</code>. + * + * @return an array with the currently subscribed listeners, or + * an empty array if there are currently no listeners. + * + * @since 1.3 + */ + public <T extends EventListener> T[] getListeners(Class<T> listenerType) + { + return listenerList.getListeners(listenerType); + } + + /** + * Returns all <code>ChangeListeners</code> that are currently + * subscribed for changes to this + * <code>DefaultBoundedRangeModel</code>. + * + * @return an array with the currently subscribed listeners, or + * an empty array if there are currently no listeners. + * + * @since 1.4 + */ + public ChangeListener[] getChangeListeners() + { + return (ChangeListener[]) getListeners(ChangeListener.class); + } + + /** + * Provides serialization support. + * + * @param stream the output stream (<code>null</code> not permitted). + * + * @throws IOException if there is an I/O error. + */ + private void writeObject(ObjectOutputStream stream) + throws IOException + { + stream.defaultWriteObject(); + } + + /** + * Provides serialization support. + * + * @param stream the input stream (<code>null</code> not permitted). + * + * @throws IOException if there is an I/O error. + * @throws ClassNotFoundException if there is a classpath problem. + */ + private void readObject(ObjectInputStream stream) + throws ClassNotFoundException, IOException + { + stream.defaultReadObject(); + listenerList = new EventListenerList(); + } + +} |